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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
Journal Basic Information
Journal DOI :
Korean Academy of Pediatric Dentistry
Editor in Chief :
Volume & Issues
Volume 26, Issue 4 - Nov 1999
Volume 26, Issue 3 - Aug 1999
Volume 26, Issue 2 - May 1999
Volume 26, Issue 1 - Feb 1999
Selecting the target year
RETENTIVE FORCES OF CLASPS OF REMOVABLE ORTHODONTIC APPLIANCES FOR CHILDREN
Han, Jeong-Jae ; Lee, Kwang-Hee ; Kim, Dae-Eop ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 207~217
The purpose of this study was to compare the retentive forces of various types of clasps for removable orthodontic appliances for primary and mixed dentition. Seven metal models of a single tooth and two teeth were made, including maxillary left primary canine, first primary molar, second primary molar and first molar. Retentive forces of Adams clasp, circumferential clasp(C clasp), Jackson clasp, Duyzing clasp, arrowhead clasp, ball clasp, eyelet clasp, and triangular clasp were measured by Universal Testing Machine(Zwick Z020, Germany). The obtained results were as follows. 1. Jackson clasp and Adams clasp showed the highest retentive force among single tooth clasps. 2. C clasp showed the lowest retentive force, and there was no statistically significant difference in retentive force between mesial end C clasp and distal end C clasp. 3. Eyelet clasp showed the highest, and ball clasp showed the lowest retentive farce among clasps for interdental undercut. 4. Triangular clasp showed higher retentive force than ball clasp.
CHANGES IN ELECTROPHYSIOLOGICAL PROPERTIES OF NEUROBIOTIN-LABELED PYRAMIDAL CELLS OF HIPPOCAMPUS RECORDED IN VIVO
Lee, Hye-Sook ; Lee, Maan-Gee-G. ; Kim, Young-Jin ; Choi, Byung-Ju ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 218~231
Pyramidal cells in the hippocampal CA area were recorded from and filled with neurobiotin in anesthetized rats. The extent of their dendrites and the electropharmacological properties of membrane as well as the effect before and after neurobiotin injection were examined. Pyramidal cells had a high resting membrane potential, a low input resistance, and a large amplitude action potential. A afterhyperpolarization was followed a single action potential. Most pyramidal cells did not display a spontaneous firing. Pyramidal cell displayed weak inward rectification and anodal break excitation in response to negative current injection into the cell. Membrane properties of recorded neurons before and after neurobiotin injection with consecutive current injection were compared. Some properties were significantly increased after labelling(P>0.05); the duration and amplitude of sustained AHP, input resistance, and the number of action potentials for simultaneous intra- and extracellular stimulations. Neurobiotin-filled neurons showed pyramidal morphology. Cells were generally bipolar dendrite processes ramifying in stratum lacunosum-moleculare, radiatum, and oriens.
PREMATURE ERUPTION OF PERMANENT SUCCESSORS : A CASE REPORT
Koo, Hyun-Jung ; Lee, Jae-Cheoun ; Hahn, Se-Hyun ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 232~239
Exfoliation of the primary teeth and eruption of the permanent teeth is a normal and predictable physiologic process. The accurate prediction of tooth development is of major importance in treatment planning for children. Norms that correspond to the child's age and development have been determined by many investigators. However, there are a variety of factors that may hasten, retard, or otherwise affect the normal developmental process. Among the factors that influence tooth eruption is the premature loss of primary teeth. An abscess of a primary molar, followed by bone resorption and early extraction or exfoliation may lead to premature eruprion of the permanent succesor, and a variety of clinical sequelae. I, hereby present the patients who have prematurely erupted permanent successor in Seoul National University Hospital Pediatric Dentistry, and report the clinical and radiologic characteristics, its sequelae, proper managements, and followed up findings.
FULL COVERAGE RESTORATION OF PRIMARY ANTERIOR TEETH : A CASE REPORT
Hong, Kee-Sang ; Jang, Ki-Taeg ; Lee, Sang-Hoon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 240~247
Primary anterior teeth requiring extensive restorative therapy due to caries, trauma or developmental defects can present a particularly challenging problem for the pediatric dentist. The ideal restorative technique would combine strength, durability esthetics and efficiency in placement. Couple these concerns with the technical difficulties of operating on children with behavior management problems, and the dentist is left with the difficult task of choosing from a variety of restorative options. Restorative modalities currently in use to treat primary anterior teeth include bonding with composite resin as in celluloid strip crowns, conventional stainless steel crowns, open-faced stainless steel crowns, commercially and chairside veneered stainless steel crowns and epoxy-coated stainless steel crowns. Each of these techniques presents technical, functional or esthetic compromises that complicate their efficient and effective usage. This is a report of the results obtained at the Department of Pediatric Dentistry, College of Dentistry Seoul National University, through the use of these various methods of treating primary anterior teeth.
A STUDY ON CEPHALOMETRIC EVALUATION OF MIXED DENTITION CHILDREN WITH NORMAL OCCLUSION
Lee, Sang-Min ; Jung, Tae-Ryun ; Hahn, Se-Hyun ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 248~261
In order to define a current set of Korean children norm with mixed dentition, following study was done. The subjects were 102 healthy dentition contestants(48boys, 54girls). Standardized lateral head roentgenograms were taken, and Ricketts analysis was done. Results were as follows: 1. Length of anterior cranial base, posterior facial height, corpus length were longer in male than in female(p<0.05), and Porion was located posteriorly in male than in female(p<0.01). 2. Through facial depth, Pogonion of male was more forwardly positioned(p<0.05), mandible was significantly steeper in female, and maxillary anterior teeth were significantly tipped forward in male(p<0.05). 3. Variables such as length of anterior cranial base, upper molar position(p<0.01) and corpus length(p<0.05) were significantly changed by age. 4. Maxillary height, facial depth, mandibular plane angle, convexity were changed by age, but not significantly(p>0.05).
A STUDY ON THE CHANGE OF SALIVARY FLUORIDE CONCENTRATION WITH TIME AFTER VARIOUS TOPICAL FLUORIDE TREATMENTS
Park, Soo-Jin ; Kim, Hyung-Doo ; Kim, Chong-Chul ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 262~274
Several alternatives for increasing the fluoride concentration in the mouth, such as water fluoridation, ingestion of fluoride supplements, fluoride paste, fluoride mouthrinse, application of fluoride gel are available. There is an impressive body of evidence that the topically deliverd fluorides are clinically effective in inhibiting the progression of dental caries. Recent studies on the cariostatic action of fluoride have indicated the importance of fluoride in the fluid environment of the teeth. The fluoride levels in unstimulated whole saliva can be considered indicative of F in the aqueous phase available for interaction with the tooth surface at a given time. The retention of F in the mouth after topical fluoride treatment is considered to be an important factor in the clinical efficacy of F. The aim of this study was to determine the elevation and clearance of fluoride in whole saliv after the following topical flouride treatments using HMDS-diffusion technique and fluoride ion electrode. The obtained results were as follow: 1. Average salivary fluoride concentration in the unstimulated whole saliva was
. Unstimulated salivary flow rate was between 0.34-0.36ml/min and there was no statistically significant difference among the groups(p>0.05). 2. Except for the immediate time after treatment, fluoride levels followed as APF gel>neutral gel>F-rinse>F-paste. There was no statistical difference between the salivary F concentration of F-paste group and that of control group after 2 hours. In case of F-rinse group, after 3 hours the concentration had dropped to baseline value. But there was statistically significant difference among the F concentraion of F gel groups and that of control group(p<0.05). 3. The mean
values were followed as neutral gel>APF gel>F-rinse>F-paste, and the values of the two former groups were significantly higher than those of the two latter groups(p<0.05).
A STUDY OF THE CORRELATION BETWEEN THE FEATURES OF MESIODENS AND COMPLICATIONS
Lee, Yoon-Seok ; Kim, Jung-Wook ; Lee, Sang-Hoon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 275~283
Authors evaluated 152 patients at the department of Pediatric Dentistry in Seoul National University Hospital through clinical records and radiographs. And the following features were studied ; age, sex distribution, number of mesiodens per patients, location, status of eruption, shape and orientation of crown, and complication. From the above results, the relationship between features of mesiodens and complications were evaluated using chi-square analysis. 1. Complications due to the presence of mesiodens did not occur in 31.6%, delayed eruption of adjacent teeth was observed in 33.6%, midline diastema in 22.4%, rotation in 8.6%, displacement in 3.3%, and crowding in 0.7% of all evaluated patients. 2. As compared with the above 8.5 year group, in the under 8.5 year group, the frequency of complications was significantly higher(P<0.05). As compared with those positioned lingually, in mesiodens labially or within the arch the frequency of complications was significantly higher(P<0.01). Also, the frequency of complications was significantly higher when the mesiodens was tuberculate in form(P<0.05). 3. Of the 104 patients with complications, the frequency of delayed eruption was significant higher in the under 8.5 year group, and in above 8.5 year group, the frequency of malocclusion was significantly higher(P<0.05). When mesiodens were located in the midline region, the frequency of malocclusion was significant higher, while in case with laterally positioned mesiodens the frequency of delayed eruption was significantly higher(P<0.01).
BOND STRENGTH OF BONDED AMALGAM USING DENIAL ADHESIVES
Kam, Dong-Hoon ; Lee, Sang-Dae ; Hahn, Se-Hyun ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 284~295
The purpose of this study was to measure and analyze the bond strength of bonded amalgam using dental adhesives and to compare this with light-curing composite resin. Sections 8mm in diameter were punched out from the labial surface of bovine anterior teeth. These were embedded in clear acrylic resin blocks with labial surface facing out. 55 specimens were made for enamel and dentin each. After dividing these into 5 groups, group 1: Superbond C&B, group 2: Panavia 21, group 3: All-Bond 2, group 4: Fuji I Glass Ionomer Luting Cement, group 5: Scotchbond Multi-Purpose(Restorative Z-100), molds with holes of 6.3mm in diameter and 1.5mm in depth were placed over the specimens. The exposed tooth surfaces were treated with adhesives and the molds were filled with amalgam. In group 5, the mold was filled with composite resin and light-cured for 40 seconds. The author measured all specimens for bond strength 24 hours after amalgam filing and analyzed fracture surfaces. The following results were obtained: 1. Among the dentin groups, groups 1, 2 and 4 showed significantly lower bond strength compared with group 5(P<0.05). 2. Among the enamel groups, group 4 showed significantly lower bond strength compared with group 5(P<0.05). 3. In group 2, 2D showed significantly lower bond strength compared with group 2E(P<0.05). Other adhesives showed no such differences in bond strength between dentin and enamel(P>0.05). 4. Cohesive failure was observed in groups 1E and 5D, while mixed failure was seen in groups 1 and 5. Only adhesive failures were noted in groups 2, 3, 4.
A STUDY ON THE DEGREE OF POLYMERIZATION OF AUTOPOLYMERIZED RESIN FOR REMOVABLE ORTHODONTIC APPLIANCE ACCORDING TO CURING TIME AND CURING METHOD
Yoo, Jong-Wook ; Jang, Ki-Taeg ; Kim, Chong-Chul ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 296~309
Autopolymerized resin facilitates a more rapid and easier means for the construction of removable orthodontic appliances than heat cured resin. But many reports reveal that more unreacted monomer is found in autopolymerized resin. It is very important to achieve maximum degree of polymerization because if polymerization is inadequate, high level of unreacted monomer has been shown to adversely affect mechanical and physical properties, and also the question of allergy or toxicity to methylmethacrylate must be considered. The purpose of this study was to compare the degree of polymerization according to curing method and curing time. Five groups were desinged ; Group 1 was polymerizied at room temperature(
) ; Group 2 in
water ; Group 3 in
water under 30psi pressure ; Group 4 in
water ; Group 5 in
water under 30psi pressure for 10 minutes, 1 hour 12 hours, 1 day and 3 days. The degree of polymerization was measured by means of Fourier Transform Infrared spectroscopy. The results were as follows: 1. The degree of polymerization increased constantly in accordance with curing time in all groups and after curing for 10 minutes, Group 1 showed significantly higher degree of polymerization after 12 hours and Group 2, Group 3, Group 4, Group 5 after 1 hour(p<0.05). 2. The degree of polymerization decreased in the order of Group 5, Group 4, Group 3, Group 2, Group 1 except when the curing time was 1 hour and 12 hours(p<0.05). 3. The degree of polymerization of Group 4, Group 5 cured at
showed significantly higher degree of polymerization than Group 2, Group 3 at
except when the curing time was 1 day(p<0.05). 4. Among Group 2, Group 3 and Group 4, Group 5, the pressure had no effect on polymerization except when the curing time was 12 hours(p<0.05). 5. Between Group 1 and Group 2, the method of storage had no effect on polymerization except when the curing time was 1 hour(p<0.05).
PULP VITALITY TEST OF TEETH AFTER TRAUMATIC INJURIES USING LASER DOPPLER FLOWMETRY - A CASE REPORT
Song, Yun-Ju ; Kim, Hyun-Jung ; Nam, Soon-Hyeun ; Kim, Young-Jin ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 310~316
In the traumatized teeth, the major complications are pulp necrosis, and root resorption. The factors influencing to prognosis are the state of root development, type of injuries, quality of fixation. There are good prognosis in the case of immature teeth, minor luxation injuries. To minimize of occurrence of these complication, it is very important to determine the pulp vitality. This can help us decide whether or not to treat the teeth endodontically. But, it is difficult to determine of pulp vitality in immature teeth or traumatized teeth. In this case, pulp vitality test was done periodically on the traumatized upper central incisors, and the results were different among cold test, electric pulp test, and laser Doppler flowmetry. The conclusions were obtained from this case can be summarized as follows; 1. Pulp vitality of traumatized teeth should be negative early, but with time going, pulp vitality could be recovered. 2. The positive response of pulp vitality test was detected earlier in laser Doppler flowmetry. 3. Between cold test and electric pulp test, cold test was more reliable in determining pulp vitality.
DENS INVAGINATUS AND A VITAL MAXILLARY LATERAL INCISOR WITH LATERAL PERIODONTAL ABSCESS
Bae, Won-Su ; Kim, Hyun-Jung ; Nam, Soon-Hyun ; Kim, Young-Jin ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 317~322
Dens invaginatus is a developmental anomaly resulting from an invagination of the enamel organ. The incidence is highest with maxillary permanent lateral incisors. The reported occurrence ranges from 0.04 to 10%. This anomaly may involve the pulp and periapical tissues and cause pulpal inflammation, loss of vitality, apical and lateral periodontitis, periapical abscesses and cysts and stimulate internal resorption. Oehlers describes dens invaginatus as occurrence in three forms. In treating type 3 invaginatus, treatment strategy can be determined by considering the complexity and accessibility of invagination. In this case, showing simple invagination, it could be treated by simple endodontic treament confining to invagination without loss of vitality of tooth. After treatment of the present case, the results were as follows: 1. In type 3 dens invagiantus, if the tooth is vital and there is no evidence of communicating between invagination and pulp, we can save the vitality of the tooth and resolve the lesion by endodontic treament confining to the invagination. 2. In the invagination with opened apex, the closure of apex can be induced by apexification procedure doing this, we can avoid the neccessity of surgical intervention.
THE TREATMENT OF AN ANTEIOR CROSS-BITE WITH THE ERUPTION OF A MAXILLARY INCISOR USING
III : CASE REPORT
Lee, Sang-Youp ; Kim, Hyun-Jung ; Nam, Sun-Heun ; Kim, Young-Jin ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 323~330
It is well recognized that a cross-bite tends to occur more frequently among Japanese, Chinese and Koreans more than among Europeans. A variety of functional appliances have already invented for the treatment of cross-bites. One of them is the FR III(by Rolf
) which applies a quite different philosophy based on the using vestibular region compared with other methods which utilize muscular forces applied directly on the teeth. The FR III also increases both the lack of muscular tension against the dental arch and the dentition and muscular forces which can then influence the teeth indirectly. This mechanism can achieve favorable developments with the basal bone, teeth, and alveolar bone. After using FR III to the anterior cross-bite patient with the eruption of a maxillary incisor the results were as follows: 1. Forward growth of maxilla and proclination of the upper incisor 2. Downward and backward rotation of the mandible 3. Increase the facial height 4. The case which was normal mandible, underdevelopmental maxilla, deeper overbite and more nagative overjet exhibited good prognosis
EFFECT OF CHEMORADIATION THERAPY ON THE DEVELOPING DENTITION : A CASE REPORT
Kim, Jae-Gon ; Kim, Young-Sin ; Yang, Jeong-Suk ; Lee, Seung-Young ; Baik, Byeong-Ju ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 331~338
Chemoradiation therapy used on pediatric oncology patients often causes dental developmental anomalies that affect future dental care. Defects noted include tooth and root agenesis, root thining and shortening, and localized enamel defects. The effect of radiotherapy usually are confined to the radiation site, but the effects of chemotherapy may be more wide spread because of its systemic distribution and structures and organs unrelated to the primary tumor may be affected. Many pediatric cancers are treated with a combination of radiation and multiagent chemotherapy to create synergic and additive effects. Dental treatment affected by chemoradiation damage to developing teeth includes orthodontic tooth movement, prosthetic abutment considerations, periodontal health, space maintenance, requirements for home fluoride regimens to protect hypomineralized areas, restoration options for hypoplastic/hypomineralized teeth, and endodontic procedures. The following case demonstrate chemoradiation therapy effects on the dental development.
THE EFFECTS OF THERMAL STIMULI TO THE FILLED TOOTH STRUCTURE
Baik, Byeong-Ju ; Roh, Yong-Kwan ; Lee, Young-Su ; Yang, Jeong-Suk ; Kim, Jae-Gon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 339~349
The dental structure substituted by restorative materials may produce discomfort resulting from hot or cold stimuli. To investigate the effects of this stimuli on the human teeth, thermal analysis was carried out by calculation of general heat conduction equation in a modeled tooth using numerical method. The method has been applied to axisymmetric and two-dimensional model, analyzing the effects of constant temperature
. That thermal shock was provided for 2 seconds and 4 seconds, respectively and recovered to normal condition of
until 10 seconds. The thermal behavior of tooth covered with a crown of gold or stainless steel was compared with that of tooth without crown. At the same time, the effects of restorative materials(amalgam, gold and zinc oxide-eugenol(ZOE)) on the temperature of PDJ(pulpo-dentinal junction) has been studied. The geometry used for thermal analysis so far has been limited to two-dimensional as well as axisymmetric tooth models. But the general restorative tooth forms a cross shaped cavity which is no longer two-dimensional and axisymmetric. Therefore, in this study, the three-dimensional model was developed to investigate the effect of shape and size of cavity. This three-dimensional model might be used for further research to investigate the effects of restorative materials and cavity design on the thermal behavior of the real shaped tooth. The results were as follows; 1. When cold temperature of
was applied to the surface of the restored teeth with amalgam for 2 seconds and recovered to ambient temperature of
, the PDJ temperature decreased rapidly to
until 3 seconds and reached to
after 9 seconds. This temperature decreased rather slowly with stainless steel crown, but kept similar temperature within
differences. Using the gold as a restorative material, the PDJ temperature decreased very fast due to the high thermal conductivity and reached near to
but the temperature after 9 seconds was similar to that in the teeth without crown. The effects of coldness could be attenuated with the ZOE situated under the cavity. The low thermal conductivity caused a delay in temperature decrease and keeps
higher than the temperature of other conditions after 9 seconds. 2. The elapse time of cold stimuli was increased also until 4 seconds and recovered to
after 4 seconds to 9 seconds. The temperature after 9 seconds was about
lower than the temperature of 2 seconds stimuli, but in case of gold restoration, the high thermal conductivity of gold caused the minimum temperature of
after 5 seconds and got warm to
after 9 seconds. 3. The effects of hot stimuli was also investigated with the temperature of
. For 2 seconds stimuli, the temperature increased to
from the initial temperature of
after 3 seconds of stimuli and decreased to
after 9 seconds in the teeth without crown. This temperature was sensitive to surface temperature in the teeth with gold restoration. It increased rapidly to
from the initial temperature of
after 2 seconds and decreased to
after 9 seconds, which showed
temperature variations for 9 seconds upon the surface temperature. This temperature variations were only in the range of
by using ZOE in the bottom of cavity and showed maximum temperature of
after 3 seconds of stimuli.
Distribution of Mast cells and Nerves in the Developing Postnatal Submandibular and Sublingual Glands of Rats
Kim, Jae-Gon ; An, Soo-Hyeon ; Lee, Young-Su ; Baik, Byeong-Ju ; Cho, Eui-Sic ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 350~364
The distribution of mast cells and nerves were investigated in the submandibular and sublingual glands of postnatal rats, using morphometric, histochemical and immunohistochemical techniques. Mast cells were observed in the submandibular and sublingual glands of postnatal development. Number of mast cells gradually increased in both glands following development. At birth, mast cells were relatively fewer in submandibular gland than those in sublingual gland, and they were mainly distributed in parenchymal tissues. At
weeks, most of the mast cells were observed in the connective tissues, surrounding neurovascular elements, but some mast cells were closely related with the acini of submandibular gland. PGP 9.5 immunoreactive nerve fibers were found in the submandibular and sublingual glands of all developmental age. The nerve fibers were showed in varicose shape, and mainly located in adjacent area of ducts and vascular components of both glands. The number of nerve fibers were increased rapidly until 8 weeks, but they were not increased any more until 24 weeks. Therefore, it is suggested that mast cells and nerve fibers related with each other, and that their interactions may play roles not only in maturation of secretory units but also growth and differentiation of the tubular structures of the rat submandibular and sublingual glands during postnatal development.
TEMPERATURE CHANGE IN THE PULP ACCORDING TO POLISHING CONDITION OF VARIOUS RESTORATIVE MATERIALS
Baik, Byeong-Ju ; Park, Jong-Ha ; Yang, Jeong-Suk ; Lee, Seung-Young ; Kim, Jae-Gon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 365~376
The importance of finishing and polishing the restoration has been described by several authors. The final step provides for improved metallurgical properties, better marginal adaptation, reduced plaque accumulation. Unfortunately, finishing of the restorations can produce damage from temperature rises at the pulpal wall. The aim of this study was to determine the changes in temperature can be occurred during the use of finishing and polishing instruments under a variety of conditions. ; with or without a water coolant, intermittent or continuous operation, high or low rotation speed, remaining dentin thickness and various restorative materials. Class V preparations were cut on extracted molars and restored with composite resin(Z 100), resin-modified glass ionomer cements(Dyract, Fuji II LC), and amalgam. Finishing was done with aluminum oxide coated disc(
polishing disc, 3M, USA). The following results were obtained. 1. The rise of temperature during polishing of amalgam restorations was the highest among the all experimental groups except polishing with water coolant(P<0.05). However, there were no statistical differences in temperature rises between Z 100, Dyract and Fuji II LC(P>0.05). 2. The intrapulpal temperature was greatly influenced by the applied time, and intermittent polishing was showed significantly lower temperature rises than continuous polishing(P<0.01). 3. The intrapulpal temperature was increased according to the application of polishing regard less of using water coolant. However, polishing with water coolant showed significantly lower temperature in the pulp than not used water coolant(P<0.01).
THE EFFECT OF ND:YAG LASER IRRADIATION ON THE FORMATION OF CALCIUM FLUORIDE AND ACID RESISTANCE OF TOOTH ENAMEL
Lee, Jae-Ho ; Sohn, Heung-Kyu ; Kim, Seong-Oh ; Park, Kwang-Kyun ; Choi, Byung-Jai ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 377~398
Calcium fluoride, created by topical fluoride application, is the reservoir for fluoride ion regulated by pH in the oral environment. Therefore, the amount and the maintenance of calcium fluoride have an important role in preventing dental caries. The aim of this study is to evaluate the effect of Nd:YAG laser irradiation on the generation of calcium fluoride and the acid resistance of tooth enamel. The bovine anterior permanent teeth were prepared (n=276), and divided into following groups : no treatment (control) fluoride application alone, laser irradiation alone, laser irradiation after fluoride application, and fluoride application after laser irradiation. And each group was subdivided based on the application time of 1.23% acidulated phosphate fluoride (APF) (5 min and 30 min) and the irradiation energy of Nd:YAG laser (
). In case of fluoride application, each group was divided according to KOH treatment. Twenty three treatment conditions were made for this experiment and twelve specimens were assigned to each treatment condition. In each treatment condition, ten specimens were used for chemical analysis and two specimens were observed under SEM. In groups without treating KOH, fluoride content and the depth of enamel dissolved were measured using enamel biopsy technique. In groups with treating KOH, the amount of calcium fluoride was measured by the treatment with 1 M KOH for 24 hours and enamel biopsy was performed after KOH treatment. The results were analyzed by the fluoride content and the depth of enamel dissolved by enamel biopsy, amount and thickness of calcium fluoride, and the surface structures of enamel. The results are as follows: 1. In groups without treating KOH, the fluoride content of removed enamel showed a positive relationship with the energy density of laser when the laser irradiated before fluoride application 2. In groups without treating KOH, the depth of enamel dissolved decreased more with the combined laser and fluoride treatment than with laser or fluoride treatment, except for the case of
laser irradiation after 5 minute fluoride application (p<0.05). 3. The amount of calcium fluoride did not increased by laser treatment with no statistical significance(p>0.05). 4. The particle size of calcium fluoride increased in case of fluoride treatment after laser irradiation, compared with fluoride application alone. In case of laser treatment after fluoride application, the particle size of calcium fluoride increased and some of the particles fused as well. 5. There were no significant differences in the fluoride content of dissolved enamel between groups without treating KOH and control group, except for the case of laser irradiation after treatment of APF for 30 minutes (p>0.05). 6. In groups with treating KOH, depth of removed enamel in the groups of combined treatment with laser and fluoride was shallower than that in fluoride application groups (p<0.05). 7. In groups without treating KOH, the relationship between fluoride content and the depth of enamel dissolved showed more negative (Spearman correlation coefficient: -0.6281) than in groups with treating KOH (Spearman correlation coefficient: -0.3792). The greater amount of calcium fluoride could be found in case where there was a significant differences of the depth of enamel dissolved between groups with and without treating KOH. From these results, it can be concluded that laser seems to be a little effects on the amount of calcium fluoride formation, but has some effect on the lowering the solubility of calcium fluoride. As the combined treatment of laser and fluoride application showed more effective acid-resistant property, more extended recall period for fluoride application can be achieved with this combined treatment in the clinic.
EFFECT OF OCTANOL, THE GAP JUNCTION BLOCKER, ON THE REGULATION OF FLUID SECRETION AND INTRACELLULAR CALCIUM CONCENTRATION IN SALIVARY ACINAR CELLS
Lee, Ju-Seok ; Seo, Jeong-Taeg ; Lee, Syng-Il ; Lee, Jong-Gap ; Sohn, Heung-Kyu ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 399~415
From bacteria to mammalian cells, one of the most important mediators of intracellular signal transduction mechanisms which regulate a variety of intracellular processes is free calcium. In salivary acinar cells, elevation of intracellular calcium concentration (
) is essential for the salivary secretion induced by parasympathetic stimulation. However, in addition to
, gap junctions which couple individual cells electrically and chemically have also been reported to regulate enzyme secretion in pancreatic acinar cells. Since the plasma membrane of salivary acinar cells has a high density of gap junctions, and these cells are electrically and chemically coupled with each other, gap junctions may modulate the secretory function of salivary glands. In this respect, I planned to investigate the role of gap junctions in the modulation of salivary secretion and
, using mandibular salivary glands of rats. In order to measure the salivary flow rate, fluid was collected from the cannulated duct of the isolated perfused rat mandibular glands at 2 min intervals.
, was measured from the cells loaded with fura-2 by spectrofluorometry. The results obtained were as follows: 1. CCh-induced salivary secretion was reversibly inhibited by 1 mM octanol, a gap junction blocker. 2. CCh-induced increase in
, was also reversed by the application of 1 mM octanol. 3. Octanol did not block the initial increase in
caused by CCh, which suggested that the reduction of
, caused by gap junction blockade was not resulted from the inhibition of
release from intracellular
stores. 4. Addition of octanol during stimulation with
thapsigargin, a potent microsomal ATPase inhibitor, reduced
, to the basal level. This suggested that inhibition of gap junction permeability closed plasma membrane
channels. 5. 2,5-di-tert-butyl-1,4-benzohydroquinone (TBQ) generated
oscillations resulting from periodic influx of
via plasma membrane. The TBQ-induced
oscillations were stopped by the application of 1mM octanol which implicated that gap junctions modulate the permeability of plasma membrane
channels. 6. Glycyrrhetinic acid, another well known gap junction blocker, also inhibited CCh-induced salivary secretion from rat mandibular glands. These results suggested that gap junctions play an important role in the modulation of fluid secretion from the rat mandibular glands and this was probably due to the inhibition of
influx through the plasma membrane
THE EFFECT OF PRIMER ON PENETRATION OF SEALANT
Jeong, Hye-Seon ; Lee, Jae-Ho ; Choi, Hyung-Jun ; Choi, Byung-Jai ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 416~426
The objective of this study is to confirm the effect of dentine bonding primer application on penetration of sealant. Extracted permanent molars were used to compare penetration success rate of control group (sealant application only) and experimental groups (sealant application after applying the primers of
Multi-Purpose system and
2 system). The following results were obtained: 1. The experimental groups using the primers showed increased sealant penetration success rate to the base of fissure when compared to control group but there was no statistically significant differences(p>0.05). 2. The depth, width and 'depth/width' value of fissure had statistically significant effect on sealant penetration success rate(p<0.05). 3. The penetration success rate decreased about 0.9 times as the depth of fissure increased every
, and increased about 1.1 times as the width of the fissure orifice increased every
and decreased about 0.6 times as the 'depth/width' value increased every 1. From the above results, it can be concluded that assure morphology had a great effect on sealant penetration and for better penetration, use of dentine bonding primer can be helpful but it needs more study in clinical bases.
A COMPARATIVE STUDY OF PRESERVING ABILITY OF HUMAN PERIODONTAL LIGAMENT CELLS STORED IN DIFFERENT STORAGE MEDIA
Choi, Won-Kyung ; Choi, Hyung-Jun ; Choi, Byung-Jai ; Lee, Jong-Gap ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 427~436
Preservation of the remaining periodontal ligament cells on an avulsed tooth is very important to the successful outcome of replantation. HBSS is recommended as the most suitable storage medium for the avulsed tooth that cannot be replanted immediately. But their availability near the site of an accident is doubtful. The purpose of this in vitro study was to compare periodontal ligament cells stored in different storage media obtained easily on the spot. Human periodontal ligament cells were collected from the premolar teeth extracted for orthodontic treatment. Cells were cultured in
culture medium containing 20% FBS, at
100% humidity, in a 5%
incubator. Cells were cultured in 96 well culture plate,
cells per well with
and incubated for 24 hours. After discarding the medium, those cells were cultured in
contained with 10% FBS, pasteurized milk, sterilized saline, unstimulated saliva and bench-dried state at
room temperature for 30, 60, 90, 120, 180 minutes respectively. And then each group was measured using MTT assay. The results were as follows. 1. Between the group of each time, there was statistically significant difference. Periodontal ligament cells viability was highest in pasteurized milk and was reduced stepwisely in sterilized saline, unstimulated saliva and bench-dried state(p<0.05). 2. between the time of each group, there was statistically significant difference(p<0.05) but was no statistically significant difference at 90-120 minutes in pasteurized milk and at 60-90 minutes and 120-180 minutes in sterilized saline(p>0.05). In conclusion, HBSS as storage medium of an avulsed tooth is not practical on the spot. Insteadily pasteurized milk can be recommended to maintain the periodontal ligament cells viability.
RELATIONSHIP BETWEEN LASER DOPPLER FLOWMETER OUTPUT AND STAGE OF ROOT DEVELOPMENT
Su, Wan-Jong ; Kim, Hyun-Jung ; Kim, Young-Jin ; Nam, Soon-Hyeun ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 437~445
The purpose of this study was to evaluate the changes of laser doppler flowmeter output associated with stage of root development. Laser Doppler Flowmeter was done in 40 elementary students aged between 7 and 8 years and in 20 adults aged between 23 and 24 years. Among 40 elementary students, 20 had apical foramens with
diameters and another 20 had ones with larger diameters than 2mm. The LDF values were analyzed with ANOVA and paired t-test. The results were as follows. 1. Immature root apecies group had a higher tendency than mature root apecies group in LDF values, but there was no statistical significance (p>0.05). 2. There was no statistical significance in LDF values comparing groups with immature root apecies (p>0.05). 3. There were no significant differences between right and left central incisors in LDF values (p>0.05).
CORRECTION OF ECTOPIC ERUPTION WITH BILATERAL ANCHORAGE : REPORT OF CASES
Ahn, Sung-Ihn ; Shun, Ye-Kyung ; Shim, Youn-Soo ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 26, issue 2, 1999, Pages 446~452
Ectopic eruption of the first permanent molar means the first permanent molar assumes an atypical path of eruption resulting in premature atypical resorption of the second primary molar. If the reversible eruption does not occur, early loss of the second primary molars results in space loss, mesial tipping of the first permanent molar, impaction of the second premolar, buccal segment crowding and overeruption of opposing tooth. The main objectives of treatment are (1) to prevent loss of the second deciduous molars so it can continue to serve as a space maintainer and (2) to regain lost arch length, allowing the second premolar to erupt into normal position. The optimal treatment approach depends on a number of factors including the clinical eruption status of /6/, the change in position of /6/, the amount of enamel ledge of /E/ entrapping /6/, the mobility of /E/, and the presence of pain or infection. Unilateral appliance to correct the mesial angulation of ectopic permanent first molars, as in the majority of the appliance designs, would produce a resultant force that would further enhance the space loss. A bilateral support similar to the holding arch design is recommended to maximize the anchorage. These case reports present the successful result of preserving space for the second premolar in treatment of ectopic eruption of the first permanent molar using Halterman appliance with bilateral anchorage on patients visiting department of pediatric dentistry in Samsung Medical Center.